1. Field of the Invention
The present invention relates generally to a noncontact web transporting apparatus, and more particularly to a noncontact web transporting apparatus that transports a web along helical routes without coming into contact with the web while reducing a bias and a snaking of the web to stabilize the transportation of the web.
2. Description of Related Art
A noncontact transporting apparatus transports a web along helical routes without coming into contact with the web, and it comprises at least two cylindrical air chambers that support the web that is running along the helical routes through air films and direction changing rollers that the web 10 enters and leaves the helical routes from and for as disclosed in Japanese Patent Publication No. 48-44151.
It is important to stably transport the web along the helical routes. Japanese Utility Model Publication No. 61-2676 and Japanese Patent Provisional Publication No. 6-144663 disclose noncontact transporting apparatuses in which direction changing rollers can incline and the position of the running web is determined and the direction changing rollers are inclined so that the web is always positioned in the middle to stably transport the web.
In the noncontact transporting apparatuses disclosed in Japanese Utility Model Publication No. 61-2676 and Japanese Patent Provisional Publication No. 6-144663 , however, the direction changing rollers are always inclined, and thus it shakes the web and causes a snaking of the web.